Supported DME Table

DME Version

Coolant Temp Sensor Pin #

MS 45.0

28 (52-pin connector)

MS 45.1

28 (52-pin connector)

MS 43

24 (52-pin connector)

MS 42

24 (52-pin connector)


Install Instructions

  • Disconnect the negative terminal on the battery. Please use caution while performing this step.


  • Wait 1 minute.
  • In the engine compartment locate the DME housing.

  • Using a T-25 screwdriver (some models may use hex screws) loosen 4 screws holding the cover in place. Swing the cover upwards to remove.



  • Remove connectors to the DME, starting with the leftmost one. The 3 inner connectors require you to push a release button from the top and swing the locking arm to release the connector.


  • Press out the 2 tabs holding the DME in place, and raise the DME upwards enough to be able to read the DME version. VERIFY THAT THE DME VERSION INSTALLED ON YOUR CAR IS SUPPORTED BY CoolantSnitch™. Consult the table above for the list of supported DMEs. In the photograph below the DME is versioned MS45.1.


  • Push the DME back down and locate the 52 pin large connector (largest one). The coolant temperature signal wire is part of this connector, it is a BROWN/RED (Brown with a Red stripe) wire. See the pin assignment table at the top for the correct DME version. After this wire is found, locate the pin # it is attached to. To do so, remove the correct sub-connector (26 pin) out of the 52 pin connector housing by pulling the tab holding the sub-connector in place and pull the sub-connector out. There could be more than one wire of the similar color, be sure to trace the wire and find one that is attached to the pin noted in the pin assignment table at the top of this document. In the photograph below pin 28 is shown which is the coolant temp signal on DME versioned MS45.1

  • After the correct wire is located, using the RED T-Tap supplied, tap into the wire above the connector assembly. Place the tap in such a way that when the connector is connected back to the DME, the T-Tap is pointing sideways and not upwards.


  • Locate the 9 pin connector to the DME that is housing power supply and ground wires. It is the rightmost connector to the DME


  • Install the 2 BLUE T-Tap connectors supplied on wires in the 9 pin connector as follows: one on the RED/WHITE/YELLOW wire and one on the BROWN Ground wire (either ground wire can be used). Tap at an angle which will cause the T-Taps to point sideways and not upwards when the connector is plugged back in.


  • Unplug the buzzer from the main CoolantSnitch housing if it is connected. Connect the CoolantSnitch™ as follows:

CoolantSnitch wire

DME wire



RED/WHITE/YELLOW Tracer (9-pin connector)

+12V Switched Power


BROWN (9-pin connector)



BROWN/RED (52-pin connector)

Coolant Temp. Signal




  • Reconnect DME connectors, make sure the plugs are fully seated and the arms are snapped back into the original position


  • Next, proceed with installing the buzzer. It will be located behind the driver’s side knee bolster

  • Installing the buzzer will involve removing the knee bolster. To do so, remove the pop-out rivet on the right side of the panel where it is connected to the center console cover.


  • Remove three phillips screws on the upper end of the panel

  • Turn the plastic screw just above the throttle assembly counter clockwise to release and pull the panel. We cautious as there are few wiring attached to the panel. Be sure not to put to much strain on them

  • Disconnect the OBD plug by pushing back the Blue Ring/Clip around it. The connector should then slip out.

  • Remove the foot well light assembly by pushing the plastic clip outwards.

  • Note, you may be able to work with the light and OBD plug connected, but be careful not to damage the wiring.

  • Next task involves bringing the buzzer wiring from the CoolantSnitch  (Gray wire) over into the cabin so that it can be connected with the buzzer. The yellow plastic section depicted below is the back side of the DME housing under the hood. You will need to use a relatively sturdy wire and push it upwards into the opening depicted below.

  • The end of the wire will appear inside the DME housing and can be used to pull the gray wiring attached to CoolantSnitch over into the cabin.

  • Secure the end of the wire and the plug for the buzzer together and pull them back into the cabin

  • Connect the buzzer to CoolantSnitch.

  • Peel the pre-attached backing tape on the buzzer and mount it on the back side of the DME box. Apply pressure for 10 seconds for the tape to adhere firmly.

  • Reconnect the battery

  • You may optionally test the device. To do so remove 2 black screws on the CoolantSnitch housing and remove the cover. The circuitry contains a mini switch as depicted below. When placed in “TEST” position, the device will set of the buzzer at approximately 68C degrees. This corresponds to the temperature gauge needle reading somewhere between the ¼ and ½ mark. Be careful not to strip the plastic screw on the mini-switch, you should feel a subtle notch when the switch is placed into either position, be sure it is fully engage.

  • If the buzzer does not get activated in the “TEST” mode by the time the needle reaches the ½ mark, retrace your steps and make sure the device is properly connected.
  • Do not forget to place the device back into its normal mode, reattach the black cover and place the device somewhere inside the DME housing. Reattach the DME cover using 4 T-25 screws.

  • Inside the cabin, raise the knee bolster panel high enough to secure the foot well light and the OBD plug back into place


  • Secure the 4 phillips screws back into place and attach the plastic rivets for the panel.
  • You are now protected against overheating!